Thanks to a recent article in Naturwissenschaften 94, 657Â–665 (2007)I learned that they found nice roadrunner like fossil footprints in China. How did they know they were roadrunner like? They had zygodactyl toes. Which means one of the front three toes is rotated clockwise so there are two forward and two back, giving footprints like a nice X look when they hit the ground. Unlike the mystery snake footprints I found above. Hopefully the article link is available to all, as they have some nice pictures of bird footyprints.